1. Field of the Description
The present description relates, in general, to design and control of robots including humanoid robots and other robots adapted for interaction with humans. More particularly, the present description relates to fabrication and control of a robot with one or more body parts (or segments or modules) that are particularly adapted for soft contact and/or interaction with a human.
2. Relevant Background
In order to interact with human environments, humanoid and other robots require safe and compliant control of the force-controlled joints. One way to achieve this goal is to equip the robot with torque-controlled joints, which have to be programmed to determine desired motions and output forces (contact forces) and, in response, to output joint torques to effectively control movement and positioning of the humanoid robot. However, it has proven difficult to provide wholly safe interactions between humans and robots simply by operating these humanoid and other robots with controlled movements.
As robotic systems become cheaper, more reliable, and more capable, their prevalence in our everyday environment continues to increase. Robots can be found providing interactive guidance or entertainment in stores and amusement parks and in more dynamic settings like homes, schools, hospitals, and the workplace where they teach, provide therapy, and lend an extra set of hands. In these more dynamic scenarios, robots and humans often work in close proximity where they physically interact with one another.
Where physical human and robot interaction is expected, it often is desirable for the robot's joints and body parts to be compliant and yielding to avoid injury and damage. For example, in nursing homes, a furry seal robot has been utilized that responds to being held and pet and helps to keep our older generations socially active and engaged. Another therapeutic robot features a sensorized silicone skin that covers its underlying mechanics. While these robots respond to touch in various ways, their motion is limited. More heavily actuated robot systems (e.g., humanoid robots) have been developed that have the ability to move with a wider variety of motions and employ soft, sensorized skins to ensure human safety during physical interaction. These robot skins can sense contact in high resolution, but they involve the use of complicated electronics. In contrast, other robots have been developed that use hard plastic shells and are adapted to work safely alongside humans by using series elastic actuators to sense contacts. This sensing method also allows users to teach the robot new tasks in a natural way by guiding its limbs and end effectors, thereby sharing their workload with the robot.